PAX6 is a DNA transcription factor that controls differentiation of the eyes and brain in divergent metazoan species. The PAX6 gene is mutated in patients with aniridia, a congenital eye malformation. This project aims to identify mutations: (1) in patients with unusual clinical findings and (2) at cis-regulatory elements surrounding PAX6. In addition, the project will screen patients with diverse types of congenital eye malformations for mutations in other, newly identified genes that are required for eye morphogenesis, such as the mammalian eyes-absent homologue Meya-1.